Browsing by Author "Ribas, I."

Now showing items 1-11 of 11

    • A candidate super-Earth planet orbiting near the snow line of Barnard's star 

      Ribas, I.; Tuomi, M.; Reiners, A.; Butler, R. P.; Morales, J. C.; Perger, M.; Dreizler, S.; Rodríguez-López, C.; Hernández, J. I. González; Rosich, A.; Feng, F.; Trifonov, T.; Vogt, S. S.; Caballero, J. A.; Hatzes, A.; Herrero, E.; Jeffers, S. V.; Lafarga, M.; Murgas, F.; Rodríguez, E.; Strachan, J. B. P.; Tal-Or, L.; Teske, J.; Toledo-Padrón, B.; Zechmeister, M.; Quirrenbach, A.; Amado, P. J.; Azzaro, M.; Béjar, V. J. S.; Barnes, J. R.; Berdiñas, Z. M.; Coleman, G.; Cortés-Contreras, M.; Crane, J.; Engle, S. G.; Guinan, E. F.; Haswell, C. A.; Henning, Th; Holden, B.; Jones, H. R. A.; Kaminski, A.; Kiraga, M.; Kürster, M.; López-González, M. J.; Montes, D.; Morin, J.; Ofir, A.; Pallé, E.; Rebolo, R.; Reffert, S.; Schweitzer, A.; Seifert, W.; Shectman, S. A.; Staab, D.; Street, R. A.; Mascareño, A. Suárez; Tsapras, Y.; Anglada-Escudé, G. (2018-11-15)
      Barnard’s star is a red dwarf, and has the largest proper motion (apparent motion across the sky) of all known stars. At a distance of 1.8 parsecs, it is the closest single star to the Sun; only the three stars in the α ...

    • The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti 

      Stock, S.; Kemmer, J.; Reffert, S.; Trifonov, T.; Kaminski, A.; Dreizler, S.; Quirrenbach, A.; Caballero, J. A.; Reiners, A.; Jeffers, S. V.; Anglada-Escudé, G.; Ribas, I.; Amado, P. J.; Barrado, D.; Barnes, J. R.; Bauer, F. F.; Berdiñas, Z. M.; Béjar, V. J. S.; Coleman, G. A. L.; Cortés-Contreras, M.; Díez-Alonso, E.; Domínguez-Fernández, A. J.; Espinoza, N.; Haswell, C. A.; Hatzes, A.; Henning, T.; Jenkins, J. S.; Jones, H. R. A.; Kossakowski, D.; Kürster, M.; Lafarga, M.; Lee, M. H.; González, M. J. López; Montes, D.; Morales, J. C.; Morales, N.; Pallé, E.; Pedraz, S.; guez, E. Rodrí; Rodríguez-López, C.; Zechmeister, M. (2020-02-07)
      Context. The nearby ultra-compact multiplanetary system YZ Ceti consists of at least three planets, and a fourth tentative signal. The orbital period of each planet is the subject of discussion in the literature due to ...

    • Evolution of the solar activity over time and effects on planetary atmospheres. II. κ1 Ceti, an analog of the sun when life arose on earth 

      Ribas, I.; Porto de Mello, G.F.; Ferreira, L.D.; Hebrard, E.; Selsis, F.; Catalan, S.; Garces, A.; do Nascimento, J.D.; de Medeiros, J.R. (2010)
      The early evolution of Earth's atmosphere and the origin of life took place at a time when physical conditions at the Earth were radically different from its present state. The radiative input from the Sun was much enhanced ...

    • The initial-final mass relationship from white dwarfs in common proper motion pairs 

      Catalan, Silvia; Isern, J.; Garcia-Berros, E.; Ribas, I.; Prieto, C. Allende; Bonanoss, A. Z. (2008-01)
      Context. The initial-final mass relationship of white dwarfs, which is poorly constrained, is of paramount importance for different aspects of modern astrophysics. From an observational perspective, most of the studies up ...

    • The initial-final mass relationship of white dwarfs in common proper motion pairs 

      Catalan, Silvia; Ribas, I.; Isern, J.; Garcia-Berro, E.; Prieto, C. Allende (Astronomical Society of the Pacific, 2007)
      A promising approach to decrease the uncertainties in the initial-final mass relationship, which is still poorly constrained, is to study white dwarfs for which external constraints are available, for instance, white dwarfs ...

    • The initial-final mass relationship of white dwarfs revisited: effect on the luminosity function and mass distribution 

      Catalan, Silvia; Isern, J.; Garcia-Berro, E.; Ribas, I. (2008-07-11)
      The initial-final mass relationship connects the mass of a white dwarf with the mass of its progenitor in the main sequence. Although this function is of fundamental importance to several fields in modern astrophysics, it ...

    • A multiplanet system of super-Earths orbiting the brightest red dwarf star GJ 887 

      Jeffers, S. V.; Dreizler, S.; Barnes, J. R.; Haswell, C. A.; Nelson, R. P.; Rodríguez, E.; Lopez-Gonzalez, M. J.; Morales, N.; Luque, R.; Zechmeister, M.; Vogt, S. S.; Jenkins, J. S.; Palle, E.; Berdinas, Z. M.; Coleman, G. A. L.; Diaz, M. R.; Ribas, I.; Jones, H. R. A.; Butler, R. P.; Tinney, C. G.; Bailey, J.; Carter, B. D.; ~O'Toole, S.; Wittenmyer, R. A.; Crane, J. D.; Feng, F.; Shectman, S. A.; Teske, J.; Reiners, A.; Amado, P. J.; Anglada-Escude, G.; . (2020-06-26)
      The closet exoplanets to the Sun provide opportunities for detailed characterization of planets outside the Solar System. We report the discovery, using radial velocity measurements, of a compact multiplanet system of ...

    • Stellar chronology with white dwarfs in wide binaries 

      Catalan, Silvia; Garces, A.; Ribas, I.; Isern, J.; Garcia-Berro, E. (Cambridge University Press, 2009)
      White dwarfs are the evolutionary end product of stars with low and intermediate masses. The evolution of white dwarfs can be understood as a cooling process, which is relatively well known at the moment;. For this reason, ...

    • Testing the initial-final mass relationship of white dwarfs 

      Catalan, Silvia; Isern, J.; Garcia-Berro, E.; Ribas, I. (2009)
      In this contribution we revisit the initial-final mass relationship of white dwarfs, which links the mass of a white dwarf with that of its progenitor in the main-sequence. Although this function is of paramount importance ...

    • Time evolution of high-energy emissions of low-mass stars : I. Age determination using stellar chronology with white dwarfs in wide binaries 

      Garces, A.; Catalan, S.; Ribas, I. (2011)
      Context : Stellar ages are extremely difficult to determine and often subject to large uncertainties, especially for field low-mass stars. We plan to carry out a calibration of the decrease in high-energy emissions of ...

    • WD0433+270: an old Hyades stream member or an Fe-core white dwarf? 

      Catalan, Silvia; Ribas, I.; Isern, J.; Garcia-Berro, E. (2008-01)
      Context. G39-27/289 is a common proper-motion pair formed by a white dwarf (WD0433+270) and a main-sequence star (BD+26 730) that apparently has been classified as a member of the Hyades open cluster. Previous studies of ...